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Finding the Fourth Proportional to 858.60, 1,288.08 and 511.80

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Solution

The fourth proportional to 858.60, 1,288.08 and 511.80 is: 767.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.60 : 1,288.08 = 511.80 : x
  2. Step 2: Convert to fraction form
    858.60/1,288.08 = 511.80/x
  3. Step 3: Cross multiply
    858.60x = 1,288.08 × 511.80
  4. Step 4: Simplify right side
    858.60x = 659,239.34
  5. Step 5: Solve for x
    x = 659,239.34/858.60
  6. Step 6: Final answer
    x = 767.81

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.